Evolución morfológica en el epitelio seminífero del Cerdo en diferentes edades (Sus scrofa de la raza Landrace)*

The morphological development of the seminiferous epithelium in the pig at different ages ( Sus scrofa , Landrace breed)
In the Pig, Landrace breed, were observed, at different ages, among 15 to 210–220 days, the morphological patterns of the seminiferous epithelium that lines "cordonal" tubules at 15 to 30 days of postnatal and "luminal" tubules at 120 to 210–220 days of age. Although some morphological events of cellular differentiation were observed at 120 days, and the spermatogenesis process apparently could be observed at 180–190 days, really the overall characteristics of the cellular differentiation in the seminiferous epithelium, with the presence of luminal spermatozoa, were observed at 210–220 days of age. This last stage is considered as the puberal age.     

Aportaciones a la Topografía Craneoencefálica de la Cabra

Radiographic projection of a median section of the brain and skull in goat This study, based on three goats, provides a radiographic projection of a median section of the brain and the skull. The method allows a topographic correlation of brain structures with the skull and surrounding osseous structures. A standard skull position, with the basic horizontal plane passing through the external acoustic meatus, and parallel to the floor of the skull, results in a method of localizing brain structures in specific transverse planes. This stereotaxic method allows investigators to account for variability in topography between animals in the localization of brain structures through external morphology.     

Involución de Germenes Dentarios en la Oveja (Ovis aries)

In this study we examined some histologic and histochemical characteristics of the embryonic sheep dental epithelium in early odontogenesis. During the first trimester of development, a short-lived dental lamina was observed. Apparently in the sheep, the interactions between epithelial and ectomesenchymal cells required for tooth normal morphogenesis are altered.     

Algunos aspectos sobre la inervación de pulmon en animales de laboratorio

The finer innervation of the tissues of the lung was studied with several methods of silver impregnation, focussing especially on the fibers and endings of the nerves. The richest terminal innervation could be found in the epithelial and subepithelial tissue, and was sometimes similar to the situation in the smooth muscles which might indicate that, somehow, secretory and motor innervation are alike morphologically. On the other hand, there were many nerve fibers in the perichondrium of the small nodules and plaques of cartilage too, although they did not enter the cartilaginous tissue. The final nerves ended in different forms, from round or ovoid masses to free "ultraterminal" filaments.     

Sur la Microvascularisation des Plexus Choroïdes des Ventricules Latéraux chez la Chèvre (Capra hircus)

The goat choroid plexus angioarchitecture of the lateral ventricles was studied under the SEM using the method of “microvascular corrosion casts”. The whole plexus is semilunar shaped and directed in an antero-posterior, latero-median fashion. In the plexus the lateral extremity is larger than the median one. All the components of the vascular bed (arteries, venes and capillaries) of the choroid plexus have interesting morpho-structural features. In particular, the capillaries are more developed than the other components and they are variously located on both sides of the plexus. The capillary network has a various organization in different zones of each side of the plexus.     

Preference of goats (Capra hircus L.) for tanniniferous browse species available in semi‐arid areas in Ethiopia

The objectives were to determine browse species preference of goats using dry matter intake (DMI) as a proxy, to compare preference when offered in combination with polyethylene glycol (PEG) and to establish relationships between browse species intake and chemical compositional data. Air‐dried leaves of Acacia etbaica, Cadaba farinosa, Capparis tomentosa, Dichrostachys cinerea, Dodonaea angustifolia, Euclea racemosa, Maerua angolensis, Maytenus senegalensis, Rhus natalensis and Senna singueana were used. Two cafeteria trials, each lasting 10 days, were conducted using four local mature male goats of 2–2.5 years receiving a daily ration of grass hay (4% of body weight) and 200 g wheat bran. In trial 1, goats were offered 25 g of each browse species for a total of 30 min with intake, time spent on consumption and the number of visits to specific browse species recorded at 10‐min intervals. In trial 2, the same procedure was followed except that 25 g of PEG 4000 was added to the daily wheat bran ration. Crude protein and neutral detergent fibre in browse species ranged from 69.0–245.5 to 159.8–560.6 g/kg dry matter (DM) respectively. Total phenols and total tannins contents ranged between 3.7–70.6 and 2.5–68.1 mg tannic acid equivalent/g DM, respectively, and condensed tannins 1.7–18.4 Abs_550 nm/g DM. Preference indicators measured in the first 10 min of browse species intake differed significantly among browse species and with PEG (p < 0.0001). Principal components explained 69.9% of the total variation in browse species DMI. Despite the high tannin levels, D. cinerea, R. natalensis and A. etbaica were the most preferred species regardless of PEG presence. Tannin levels at the observed browse species DMI did not determine preference, instead, preference appeared to be based on hemicellulose. Determining browse species preference is essential to exploit them to improve nutrient utilization and control parasites in goats.     

Cronología de Osificación Postnatal de las Articulaciones del Hombro y Codo en el Gato Siamés (Felts catus L.)

Chronology of the postnatal ossification of the shoulder and cubit joints of the Siam cat (Felts catus L.) A study was done by radiological techniques to show the chronology of ossification of the shoulder and cubit joints in the Siam cat, from birth up to the 25th week of postnatal development. For this experiment we used 40 little cats (19 males and 21 females) belonging to 11 litters subjected to different controls: pattern race, healthy, feeding, growing up and radioactivity. The time of the appearance and the evolution of the ossification centers is determined as well as the phenomenon of fusion during this time. The postnatal ossification from both joints of the Siam cat is compared with that of the common cat.     

Anatomy of the Cranioencephalic Structures of the Goat (Capra hircus L.) by Imaging Techniques: A Computerized Tomographic Study

A topographic study of the cranioencephalic structure was carried out by computerized tomography on Canarian breed adult goats of medium size and weight, with similar cephalic parameters. In this way, transversal, sagittal and horizontal tomographic images were obtained. Identification of the observed anatomic structures represents the basis of this work from which applicable specie data are derived.     

Mecanismos de Desarrollo de la Cúpula en los Conductos Semicirculares de las Aves: I. Secreción Celular

A study of the crista ampullaris of the vestibular apparatus was carried out in chicken embryos. The study group included embryos between stages 24 and 39 of Hamburger-Hamilton. This study elucidates the relationship of the cupula with respect to the epithelium of the crista ampullaris. With electron microscopic examination, the rough endoplasmic reticulum of the crista epithelial sustentacular cells at developmental stage of 31 H-H, demonstrated dilatations containing secretory material. Vesicles, with adhering ribosomes appear to be formed from these dilatations. At later stages of development, the vesicular material took on the characteristics of the fibrillary material composing the cupula. In some cells, secretory vesicles are seen near the apical border of these cells, where they apparently secrete vesicular contents into the endolymphatic space, contributing to the formation of the cupula.     

Recherche Tomodensitométrique sur la Topographie Stéréotaxique des Espaces Méningés de la Vache (Bos taurus L.)

Tomodensitometric examinations of the stereotaxic anatomy of the bovine intrameningeal spaces
The head of a Holstein cow was selected from seven available ones in order to produce a series of tomodensitometric transverse and sagittal sections according to Horsley-Clarke. These sections make it possible to show the stereotaxic topography of the intrameningeal spaces (Sinus epidurales and Cisternae arachnoideales) in Bos taurus.
The discussion includes suggestions for new terms for three of the spaces—Sinus condylaris, Cisterna cerebrocerebellaris and Cisterna basilaris.     

Observaciones en el punto de unión neuroectodermo-ectodermo no neural en embriones de pollo en neurulación tratados con citocalasina B ≪in ovo≫

Observations in the point of union of the neuroectoderm with the nonneural ectoderm in chick embryos after treatment "in ovo" with cytochalasin B during neurulation
Treatment of "in ovo" chick embryos with cytochalasin B during neurulation resulted in the failure of formation of the neural folds, producing an alteration in the point of union of the neuroectoderm with the nonneural ectoderm in its final development. This alteration consisted in the appearance of folding and superposition of both epithelia in this zone. The results support a possible role of the apical microfilaments in neuroectoderm and nonneural ectoderm in the process of neurulation.